2.3 1 & 4 cylinder missfire

[ritttzz]

94 Ranger 2.3 dual plug
Im looking at Koeo - 172, 211, 223?, 224, 336
Koer - 412, 332, 411

Whats been done.. Wiggle test on all plugs and inspected. All hoses inspected.
New plugs and wires, including switching misfiring plug wires which showed all to be good, including checking for spark against engine for during missfire to show sparkplugs in 1 & 4 were not reason for missfiring on those cylinders.
Coil pack tested good @ Autozone.
Egr tested with vacuum source, holds, engine almost stalls...so tested good.
New battery
Map sensor good
Dpfe module not tested.
Dis module not tested.

On coil pack with plug wires going to the intake side, this has a intermintent missfire on 1 & 4, but not on 2 & 3. Swapping plug wires confirmed wires are good on 1 & 4. Holding 1 & 4 close to a metal surface on the engine block confirms the intermittant spark on 1 & 4.

My question is to understand how the electronics works together...

Does the Dis module send a spark signal to each individual cylinder on the coil pack to fire? I noticed when i put a timing light on 1 & 4 that they both show timing mark @ about 20* and both are missfiring. Im assuming they both fire simutaneously with only one cylinder being at tdc and the other just a wasted spark with one signal to fire coming from the Dis module. Is this correct?

2nd question is the Dis module a fail or no fail part? In other words... can it just send a signal to 2 & 3 on the coil pack and not to 1 & 4?

3rd question is could this be a crankshaft position sensor(if i have one), and if it is malfunctioning send a reliable signal only to 2 & 3 and erractic signal to 1 & 4, or is this also a fail or no fail part?

Thanks for your help.

 

[Bryan22]

172, i'd check the o2 sensor. you are on the right track with the ignition system, a ICM(DIS) can be bad and the truck will still run sometimes. For the crank sensor, it usually works or it dosent. It's a simple sensor. Also the 336 code probably is the DPFE, so far i've not found a way to test the DPFE, but every time i get a code 336 or 337 i just go to autozone and get a new one under warranty and it cures the code.